To assess and compare the accuracies of intraoral scanners (IOS) and stereophotogrammetry
(SPG) devices for complete-arch digital implant impressions.A 4-analog model was digitized
using a desk scanner to obtain a reference file. Thirty test scans were conducted
using the investigated IOS device, while an additional 30 scans were performed using
the SPG device. Using the best-fit algorithm, the resulting 60 test files were aligned
with the reference file. Linear (ΔX, ΔY, and ΔZ-axis) and angular deviations (ΔANGLE)
were evaluated. Three-dimensional (3D) deviation was calculated based on the Euclidean
distance (ΔEUC). The analysis was stratified according to the scanning device and
implant position. Fisher's F and t-tests were used to compare the variances and expected
values of the two scanning systems.IOS expressed a higher 3D (ΔEUC) mean deviation
than SPG (52.8 µm vs. 33.4 µm, P < 0.0001), with extreme measurements up to 181.9
µm. A significantly higher standard deviation (SD) was associated with IOS (37.1 µm
vs. 17.7 µm, P < 0.0001). Considering angular deviations, the IOS showed slightly
higher angular mean deviations (ΔANGLE) than the SPG (0.28° vs. 0.24°, P = 0.0022),
with extreme measurements of up to 0.73°. The SPG SD values were significantly lower
than the IOS SD values (0.14° vs. 0.04°, P < 0.0001).The SPG showed significantly
higher 3D and angular accuracies for complete arch implant impressions, with consistent
repeatability. IOS scanning revealed significantly higher extreme deviations exceeding
the acceptable threshold value. Despite study limitations, SPG appears more feasible
than IOS for complete-arch digital implant impressions.
